Install & Anchoring

Ventilation

Also known as: shelter vents, passive ventilation

Sizing the ventilation

Ventilation is sized to occupancy and expected sheltering time. A two-person shelter and an eight-person shelter need very different free vent areas. The installer should provide a calculation, not a default vent count.

Common vent designs

• Hooded steel vents with internal baffles
• Through-door grilles tested as part of the door assembly
• Below-grade vent stacks with debris filters

Authority: ICC 500, FEMA P-320. Last reviewed 2026-06-04.